This invention relates to conveyors and, more particularly, to lubricating systems for multiple idler arrangements.
Many conveying systems are formed with idlers mounted on a hollow spindle or shaft through appropriate bearing configurations. These systems include multiple idler arrangements which form a catenary where adjacent idlers are connected to each other through a support joint and to the roller housing at the outer ends of the arrangement. Conveyor systems can also be formed where both ends of each idler roller are connected to a supporting housing instead of the idlers supporting themselves.
For both supported and catenary arrangements, there are advantages to providing what is called "flow-through" lubrication where the idler shafts, which are hollow and communicate with their associated bearing assemblies, are connected to each other so that all the idlers in the arrangement can be lubricated simply by applying lubrication at one end of the arrangement. The connection between adjacent hollow idler shafts has been formed by a flexible tube which can be connected to the adjacent shafts by appropriate means. These flexible connectors are effective in accommodating relative movement between adjacent idlers. Examples of the use of such flexible tube connectors can be found in U.S. Pat. Nos. 3,809,211; 3,892,306; and 3,338,381.
Although the use of flexible tubes has been found to be satisfactory, installation is relatively complicated and time consuming. Further, even though the tube is flexible, problems could occur with the catenary idlers where adjacent idlers can shift relative to each other an amount greater than the flexure capability of the tube, causing rupture. In addition, should lubricant be injected into the system under a pressure too great to be accommodated by the flexible tube, rupture or tube expulsion could also occur.